package com.swq.java.code.chapter19.code04;

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class FlowLayoutDemo {
    public static void main(String args[]) {
        final JFrame f = new JFrame("Hello");

        JPanel jPanel = new JPanel();
        final FlowLayout fl = (FlowLayout) jPanel.getLayout();
        f.setContentPane(jPanel);

        JButton leftButton = new JButton("left");
        leftButton.addActionListener(new ActionListener() {  //注册事件监听器
            public void actionPerformed(ActionEvent event) {
                fl.setAlignment(FlowLayout.LEFT);  //左对齐
                fl.layoutContainer(jPanel);  //使面板重新布局
            }
        });

        JButton centerButton = new JButton("center");
        centerButton.addActionListener(new ActionListener() {  //注册事件监听器
            public void actionPerformed(ActionEvent event) {
                fl.setAlignment(FlowLayout.CENTER);  //居中对齐
                fl.layoutContainer(jPanel);  //使面板重新布局
            }
        });

        JButton rightButton = new JButton("right");
        rightButton.addActionListener(new ActionListener() {  //注册事件监听器
            public void actionPerformed(ActionEvent event) {
                fl.setAlignment(FlowLayout.RIGHT);  //右对齐
                fl.layoutContainer(jPanel); //使面板重新布局
            }
        });

        jPanel.add(leftButton);
        jPanel.add(centerButton);
        jPanel.add(rightButton);

        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.setSize(300, 100);
        f.setVisible(true);
    }
}